This invention relates to 2-equivalent coupler compounds for oxidative hair dye compositions, some of which are also novel compounds, 1,5-disubstituted-2,4-dinitrobenzene intermediary compounds thereof, as well as to oxidative hair dyeing compositions and hair dyeing methods using these coupler compounds. More particularly, this invention relates to a class of 2-equivalent oxidative hair dye coupler compounds which are meta-phenylenediamines with additional substituents at the 1-position and at the 5-position of the benzene ring. During the oxidative coupling reaction between the oxidative dye coupler and an oxidation developer or base, the 5-substituent is eliminated.
Oxidative dye couplers based on meta-disubstituted benzene compounds, such as meta-phenylenediamine and aminophenol compounds are well known and are highly desirable for their ability to form substantive and strongly colored hair dyes in various colors upon reaction with suitable oxidation developers.
One of the earliest known successful meta-phenylenediamine coupler compounds was meta-diaminoanisol disclosed by Erlenbach in U.S. Pat. No. 992,947. In U.S. Pat. No. 1,144,181, Erhlenbach and Marks disclosed that additional stability to these coupler compounds is provided by using them in the form of their salts, such as the hydrochloride salt.
Nevertheless, the art has actively sought for new oxidative dye couplers are dermatologically and toxicologically innocuous and which possess other properties required for hair dye compositions, such as color intensity and fastness, stability, absorbability to the hair and the like.
U.S. Pat. No. 1,940,757 to Lehmann, et al discloses derivatives of phenylalkylsulfides of the formula ##STR2##
in which R represents phenyl, halogenophenyl, alkylphenyl, hydroxyphenyl or alkoxyphenyl, X represents alkyl or hydroxyalkyl, z and z' represent hydrogen, alkyl or hydroxyalkyl and n is 1 or 2.
Seemuller, in U.S. Pat. No. 3,184,387, discloses polyaminophenols of the formula ##STR3## and, in U.S. Pat. No. 3,134,721, polyaminophenols of the formula ##STR4##
wherein R.sub.1 and R.sub.2 each represent a hydrogen atom, a lower alkyl group or a lower hydroxyalkyl group with the proviso that at least one of them represents a hydrogen atom and X represents halogen, amine, hydroxyl, carboxyl, lower alkyl, lower alkoxy or nitro.
More recently, meta-phenylenediamine oxidative hair dye couplers of the formula ##STR5##
wherein R is either hydrogen, C.sub.1 -C.sub.3 alkyl or C.sub.1 -C.sub.3 hydroxyalkyl and Z represents hydroxyalkyl, alkoxyalkyl, mesylaminoalkyl, acetylaminoalkyl, ureidoalkyl or carbethoxyaminoalkyl, except that Z is not hydroxyethyl when R is hydrogen, are disclosed by Bugaut, et al in U.S. Pat. Nos. 4,125,367 and 4,259,261.
Other aminophenol and meta-phenylenediamine oxidative hair dye couplers are disclosed in U.S. Pat. Nos. 3,546,293--Kalopissis, et al, 3,558,259--Kalopissis, et al, 3,811,831--Bugaut, et al, 4,171,203--Rose, et al, and 4,323,360--Bugaut.
U.S. Pat. No. 3,005,143 to Bohm, et al relates generally to a method for manufacturing aromatic diamines having an alkyl or alkoxy substituent with up to 6 carbon atoms. The product compounds are described as intermediate products for the manufacture of dyestuffs and diisocyanates.
In U.S. Pat. No. 1,919,580 to Wagner, et al, compounds of the formula ##STR6##
wherein X represents hydrogen, nitro, or amino, are disclosed as compounds having yellow coloration.
U.S. Pat. No. 2,056,299 to Sexton discloses hydroquinone di(.beta.-alkoxyethyl)-ethers and amino and acylamino derivatives thereof which are useful in the manufacture of azo dyestuffs.
Compounds of the formula ##STR7##
wherein R may be a C.sub.2 -C.sub.6 alkylene or oxyalkylene group and X and Y may each be, independently of the other, hydrogen, halogen, C.sub.1 -C.sub.4 alkyl or alkoxy and amino (NH.sub.2) are known from Tinsley, et al U.S. Pat. No. 3,037,057. These compounds are disclosed as dye intermediates, particularly cellulose alkylcarboxylate esters, as well as for their utility as cross-linking or hardening agents for various resin compositions, particularly, epoxy resins.
A discussion of 2-equivalent and 4-equivalent couplers for benzoquinone imines is provided by John F. Corbett at J. Chem. Soc. Vol. Perkin II, 1972, pp. 999-1005. The reaction mechanism, and kinetics of the reaction, between 2,4-diamino-1,5-dimethoxy-benzene (4,6-dimethoxy-m-phenylenediamine) and benzoquinone mono-imine or benzoquinone di-imine are studied and the author concludes that in these reactions 2,4-diamino-1,5-dimethoxybenzene behaves as a 2-equivalent coupler in which a methoxy group is displaced. No practical application of this reaction is described, however. Furthermore, as will be shown hereinafter, the dimethoxy m-phenylenediamine compound does not produce a colorfast hair dye composition.
Accordingly, there is still a need in the art for further improvements in oxidative couplers for hair dyeing compositions, especially for compounds which undergo rapid reaction with the oxidation developer without requiring excessive amounts of oxidizing agents, such as hydrogen peroxide, and which have improved colorfastness.